The purpose of this study is to determine if low flow, buffered, asanguinous solutions (Krebs-bicarbonate buffer with glucose) can prevent ischemic myocardial damage during cardiopulmonary bypass with aortic cross-clamp. Recent work suggests that intracellular acidosis initiates the sequence of events which lead to ischemic damage. In addition, energy production by anaerobic pathways may be sufficient to support the nonworking heart. Providing this solution to the coronary bed may prevent acidosis and promote glycolysis.